; (function (window) {
	
	var ctx,
	hue,
	logo,
	form,
	buffer,
	target = {},
	tendrils = [],
	settings = {};
	
	settings.debug = true;
	settings.friction = 0.5;
	settings.trails = 20;
	settings.size = 50;
	settings.dampening = 0.25;
	settings.tension = 0.98;
	
	Math.TWO_PI = Math.PI * 2;
	
	// ========================================================================================
	// Oscillator 浣曢棶璧�
	// ----------------------------------------------------------------------------------------
	
	function Oscillator(options) {
	this.init(options || {});
	}
	
	Oscillator.prototype = (function () {
	
	var value = 0;
	
	return {
	
	init: function (options) {
	this.phase = options.phase || 0;
	this.offset = options.offset || 0;
	this.frequency = options.frequency || 0.001;
	this.amplitude = options.amplitude || 1;
	},
	
	update: function () {
	this.phase += this.frequency;
	value = this.offset + Math.sin(this.phase) * this.amplitude;
	return value;
	},
	
	value: function () {
	return value;
	}
	};
	
	})();
	
	// ========================================================================================
	// Tendril hovertree.com
	// ----------------------------------------------------------------------------------------
	
	function Tendril(options) {
	this.init(options || {});
	}
	
	Tendril.prototype = (function () {
	
	function Node() {
	this.x = 0;
	this.y = 0;
	this.vy = 0;
	this.vx = 0;
	}
	
	return {
	
	init: function (options) {
	
	this.spring = options.spring + (Math.random() * 0.1) - 0.05;
	this.friction = settings.friction + (Math.random() * 0.01) - 0.005;
	this.nodes = [];
	
	for (var i = 0, node; i < settings.size; i++) {
	
	node = new Node();
	node.x = target.x;
	node.y = target.y;
	
	this.nodes.push(node);
	}
	},
	
	update: function () {
	
	var spring = this.spring,
	node = this.nodes[0];
	
	node.vx += (target.x - node.x) * spring;
	node.vy += (target.y - node.y) * spring;
	
	for (var prev, i = 0, n = this.nodes.length; i < n; i++) {
	
	node = this.nodes[i];
	
	if (i > 0) {
	
	prev = this.nodes[i - 1];
	
	node.vx += (prev.x - node.x) * spring;
	node.vy += (prev.y - node.y) * spring;
	node.vx += prev.vx * settings.dampening;
	node.vy += prev.vy * settings.dampening;
	}
	
	node.vx *= this.friction;
	node.vy *= this.friction;
	node.x += node.vx;
	node.y += node.vy;
	
	spring *= settings.tension;
	}
	},
	
	draw: function () {
	
	var x = this.nodes[0].x,
	y = this.nodes[0].y,
	a, b;
	
	ctx.beginPath();
	ctx.moveTo(x, y);
	
	for (var i = 1, n = this.nodes.length - 2; i < n; i++) {
	
	a = this.nodes[i];
	b = this.nodes[i + 1];
	x = (a.x + b.x) * 0.5;
	y = (a.y + b.y) * 0.5;
	
	ctx.quadraticCurveTo(a.x, a.y, x, y);
	}
	
	a = this.nodes[i];
	b = this.nodes[i + 1];
	
	ctx.quadraticCurveTo(a.x, a.y, b.x, b.y);
	ctx.stroke();
	ctx.closePath();
	}
	};
	
	})();
	
	// ----------------------------------------------------------------------------------------
	
	function init(event) {
	
	document.removeEventListener('mousemove', init);
	document.removeEventListener('touchstart', init);
	
	document.addEventListener('mousemove', mousemove);
	document.addEventListener('touchmove', mousemove);
	document.addEventListener('touchstart', touchstart);
	
	mousemove(event);
	reset();
	loop();
	}
	
	function reset() {
	
	tendrils = [];
	
	for (var i = 0; i < settings.trails; i++) {
	
	tendrils.push(new Tendril({
	spring: 0.45 + 0.025 * (i / settings.trails)
	}));
	}
	}
	
	function loop() {
	
	if (!ctx.running) return;
	
	ctx.globalCompositeOperation = 'source-over';
	ctx.fillStyle = 'rgba(8,5,16,0.4)';
	ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
	ctx.globalCompositeOperation = 'lighter';
	ctx.strokeStyle = 'hsla(' + Math.round(hue.update()) + ',90%,50%,0.25)';
	ctx.lineWidth = 1;
	
	if (ctx.frame % 60 == 0) {
	console.log(hue.update(), Math.round(hue.update()), hue.phase, hue.offset, hue.frequency, hue.amplitude);
	}
	
	for (var i = 0, tendril; i < settings.trails; i++) {
	tendril = tendrils[i];
	tendril.update();
	tendril.draw();
	}
	
	ctx.frame++;
	ctx.stats.update();
	requestAnimFrame(loop);
	}
	
	function resize() {
	ctx.canvas.width = window.innerWidth;
	ctx.canvas.height = window.innerHeight;
	}
	
	function start() {
	if (!ctx.running) {
	ctx.running = true;
	loop();
	}
	}
	
	function stop() {
	ctx.running = false;
	}
	
	function mousemove(event) {
	if (event.touches) {
	target.x = event.touches[0].pageX;
	target.y = event.touches[0].pageY;
	} else {
	target.x = event.clientX
	target.y = event.clientY;
	}
	event.preventDefault();
	}
	
	function touchstart(event) {
	if (event.touches.length == 1) {
	target.x = event.touches[0].pageX;
	target.y = event.touches[0].pageY;
	}
	}
	
	function keyup(event) {
	
	switch (event.keyCode) {
	case 32:
	save();
	break;
	default:
	// console.log(event.keyCode); hovertree.com
	}
	}
	
	function letters(id) {
	
	var el = document.getElementById(id),
	letters = el.innerHTML.replace('&amp;', '&').split(''),
	heading = '';
	
	for (var i = 0, n = letters.length, letter; i < n; i++) {
	letter = letters[i].replace('&', '&amp');
	heading += letter.trim() ? '<span class="letter-' + i + '">' + letter + '</span>' : '&nbsp;';
	}
	
	el.innerHTML = heading;
	setTimeout(function () {
	el.className = 'transition-in';
	}, (Math.random() * 500) + 500);
	}
	
	function save() {
	
	if (!buffer) {
	
	buffer = document.createElement('canvas');
	buffer.width = screen.availWidth;
	buffer.height = screen.availHeight;
	buffer.ctx = buffer.getContext('2d');
	
	form = document.createElement('form');
	form.method = 'post';
	form.input = document.createElement('input');
	form.input.type = 'hidden';
	form.input.name = 'data';
	form.appendChild(form.input);
	
	document.body.appendChild(form);
	}
	
	buffer.ctx.fillStyle = 'rgba(8,5,16)';
	buffer.ctx.fillRect(0, 0, buffer.width, buffer.height);
	
	buffer.ctx.drawImage(canvas,
	Math.round(buffer.width / 2 - canvas.width / 2),
	Math.round(buffer.height / 2 - canvas.height / 2)
	);
	
	buffer.ctx.drawImage(logo,
	Math.round(buffer.width / 2 - logo.width / 4),
	Math.round(buffer.height / 2 - logo.height / 4),
	logo.width / 2,
	logo.height / 2
	);
	
	window.open(buffer.toDataURL(), 'wallpaper', 'top=0,left=0,width=' + buffer.width + ',height=' + buffer.height);
	
	// form.input.value = buffer.toDataURL().substr(22);
	// form.submit(); hovertree.com
	}
	
	window.requestAnimFrame = (function () {
	return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (fn) { window.setTimeout(fn, 1000 / 60) };
	})();
	
	window.onload = function () {
	
	ctx = document.getElementById('canvas').getContext('2d');
	ctx.stats = new Stats();
	ctx.running = true;
	ctx.frame = 1;
	
	logo = new Image();
	logo.src = 'ht' + 'tp://ho' + 'vertree.c' + 'om/themes/hvtimages/hvtlogo.p' + 'ng';
	
	hue = new Oscillator({
	phase: Math.random() * Math.TWO_PI,
	amplitude: 85,
	frequency: 0.0015,
	offset: 285
	});
	
//		letters('h1');
//		letters('h2');
	
	document.addEventListener('mousemove', init);
	document.addEventListener('touchstart', init);
	document.body.addEventListener('orientationchange', resize);
	window.addEventListener('resize', resize);
	window.addEventListener('keyup', keyup);
	window.addEventListener('focus', start);
	window.addEventListener('blur', stop);
	
	resize();
	
	if (window.DEBUG) {
	
	var gui = new dat.GUI();
	
	// gui.add(settings, 'debug');
	settings.gui.add(settings, 'trails', 1, 30).onChange(reset);
	settings.gui.add(settings, 'size', 25, 75).onFinishChange(reset);
	settings.gui.add(settings, 'friction', 0.45, 0.55).onFinishChange(reset);
	settings.gui.add(settings, 'dampening', 0.01, 0.4).onFinishChange(reset);
	settings.gui.add(settings, 'tension', 0.95, 0.999).onFinishChange(reset);
	
	document.body.appendChild(ctx.stats.domElement);
	}
	};
	
	})(window);